Patients with unipolar depression and bipolar illness typically show cognitive deficits, most consistently in areas reflecting right hemisphere or nondominant hemisphere brain functioning. These deficits are evidenced as problems in attention, perception, learning, and memory. Additionally, mood disorders typically are first reported at or following adolescence. To examine relations among brain structural measures, cognitive function, and psychiatric status (and to examine their covariance across the pubertal years), offspring from families in which there is parental affective illness and offspring from normal control families were studied. Two children from each family underwent magnetic resonance imaging (MRI), neuropsychological testing, and psychiatric and behavioral evaluation. Mothers also underwent the MRI procedure. These families are a subsample of an ongoing longitudinal study of the offspring of affectively ill parents and the offspring of well parents. Data collection is completed. Coding and scoring of measures are underway.